This add-on is not compatible with your version of Firefox because of the following:

Version 4.1.6
Released February 20, 2012
278.5 kB
Works with
Firefox 3.6 and later

- fixes an error introduced in version 4.1.5 whereby Firefox 3.6 became unusable for most users because help information overwrote the bottom part of the browser window- some of the help popups on settings pages weren't working- the yellow bar for creating a new SearchMenu wasn't showing if the add-on bar was disabled